When drafting, what maintains the vacuum?

When drafting, what maintains the vacuum?

• A. The movement of water through the pump
• B. Priming the pump
• C. The water level in the intake
• D. The relief valve

Answer: (A)

When drafting, keeping a vacuum on the suction side comes from priming the pump. Priming fills the pump and the suction hose with water, pushing out the air so a continuous column of water can be drawn up from the source. With the suction line primed, atmospheric pressure can push water into the pump and sustain that suction as the pump rotates. The fact that water starts moving through the pump is a result of having a prime and the suction being established, not what maintains the vacuum itself. The water level in the intake matters because if air can enter the line (due to a poor prime or an air-filled intake), the suction breaks. The relief valve handles pressure on the discharge side and does not keep the suction vacuum.

When drafting, keeping a vacuum on the suction side comes from priming the pump. Priming fills the pump and the suction hose with water, pushing out the air so a continuous column of water can be drawn up from the source. With the suction line primed, atmospheric pressure can push water into the pump and sustain that suction as the pump rotates. The fact that water starts moving through the pump is a result of having a prime and the suction being established, not what maintains the vacuum itself. The water level in the intake matters because if air can enter the line (due to a poor prime or an air-filled intake), the suction breaks. The relief valve handles pressure on the discharge side and does not keep the suction vacuum.